Athletic shoes typically include a bottom portion for providing traction and cushioning, and an upper for holding the foot of the wearer to the bottom portion. An athletic shoe may include a standard lace closure and a shank for added upper support. Bottoms are usually comprised of an outsole and a midsole. The outsole is typically constructed from a durable material like rubber that resists wear and provides traction with a contact surface. The midsole, located between the upper and the outsole, comprises a middle layer of an athletic shoe and is typically constructed from a soft foam material such as EVA (ethylene vinyl acetate) to lessen the impact forces caused during athletic activity. The foam midsole may include other cushioning elements, such as an air bladder and a shank to provide added stiffness and stability. An insole layer is usually a thin padded member made from EVA or PU (polyurethane) that is inserted into and rests at the base of the upper for added cushioned comfort.
In general, athletic shoes are designed with symmetrical medial and lateral sides of support. However, such designs do not take into account each athlete's individual physiology. For example, gait assessments classify an athlete's footstrike into three categories: neutral, underpronation and overpronation. A neutral footstrike is considered normal, whereas underpronators (supinators) tend to footstrike on a lateral (outside) portion of their shoes, and overpronators tend to roll their footstrike on the medial (inside) portion of their shoes, thereby creating instability and inefficiency that may lead to early fatigue and injury. Even athletes with neutral footstrikes require stability considerations. Accordingly, an article of footwear must meet a variety of gait characteristics to meet performance goals and minimize injury. U.S. Pat. No. 6,108,943 discloses lateral stability along the entire length of an upper which may be undesirable for an athlete who overpronates.
U.S. Pat. No. 8,074,379 is a recent attempt to fasten a shoe around a wearer's foot with a cable system and shank but it repeats the same failures that conventional lace and eyelet systems have caused for many years. Binding, release, and mechanical failures continue to plague mechanical type reel systems, especially when grit and grime are introduced into a myriad of multiple layers of small toothed gears. Such reel based closure systems also incorporate a shank, but are only capable of applying equal tension across the entire arch and instep.
U.S. Pat. No. 5,647,104 discloses a cable closure system comprising two cinching members, three spaced apart guide members and an anchoring member. However, numerous spaced apart guides on a shoe upper do not allow for strategic multiple closure systems due to the limited area in which to locate them. A further limitation in the '104 patent involves an increased amount of varying cable lengths due to adjustment limitations across a smaller anchoring area and the inability to adjust the cable length across fixed guide members.
Additionally, U.S. Pat. No. 5,319,866 discloses a split midsole design with a cookie arch support for pronators. However, such a design would be unsuitable for a neutral footstrike or underpronator. Furthermore, midsoles, outsoles, and uppers in this asymmetrical configuration do not work in concert to provide a more stable article of footwear. Instead, without the midsole support, an athlete is more likely to overpronate, thereby defeating the purpose of adding a cookie arch support between the midsole and the upper.
Orthotic inserts, otherwise known as “orthotics,” are stability enhancers that may include cushioning properties and rigid material. Orthotics are typically inserted into and rest at the base of the upper in direct contact with the wearer's feet. Orthotics come in a variety of densities. Soft orthotics are typically made from a foam material in attempt to match the contour of a respective foot. Although a soft orthotic attempts to provide a cushioning effect, it provides minimal stability support. Cushioning is desirable in most athletic shoes, but the primary benefit of an orthotic insert is its ability to control and stabilize the motions of a footstrike as it completes the gait cycle. From foot flex to absorb heel impact loads, to a more rigid toe-off phase, the primary goal of the orthotic device is to maintain proper control of the impact forces involved. Soft orthotics barely exert enough control over the gait cycle to meet the high demands of an otherwise rigid requirement. Over the course of their development, soft orthotics have evolved to include stiffeners that provide more support than a foam based material. For example, some soft orthotics include a rigid thermoplastic structure in strategic areas, but such systems are still compromised due to the soft compressible foam material associated with soft orthotics.
Rigid orthotic inserts described in U.S. Pat. No. 6,976,322, are thinner than soft orthotic inserts, and offer increased control and stability. However, rigid orthotics are often too stiff against the foot when placed in an upper, causing undesirable discomfort and occupying valuable interior footbed space in an otherwise minimally constructed upper with superior strength to weight characteristics. Most athletes find custom orthotics made by prescription cost prohibitive, and the benefits they seek may be achieved by using a standardized orthotic in conjunction with a more intelligently constructed article of footwear.
Accordingly, there exists a need for an orthotic insert in the form of a shank having sufficient rigidity to properly control the motions of the foot that can be manufactured efficiently and at low cost. Furthermore, in view of the above shortcomings, there exists a need for an orthotic that has sufficient resilient flexibility so that it is able to provide stability to the foot and shoe as the foot progresses through the gait cycle. Still further, there exists a need for a thin soft insole layer since existing orthotic inserts are typically rigid, semi-rigid, or constructed from a combination of soft foam and rigid materials that may cause crowding and raise the foot out of the heel pocket creating discomfort or deterring optimum athletic performance. Additionally, there exists a need for an orthotic that does not encumber the interior of an upper yet controls lateral and medial portions of the upper in combination with a closure system that can apply independent tensioning means across an arch and instep with a bottom that provides added stability according to an athlete's individual physiology. And finally, there is a need for a closure system that provides a fastening cable with more effective length options to achieve a more customized fit of the shoe.